Atomic layer deposition methods

ABSTRACT

A first precursor gas is flowed to the substrate within the chamber effective to form a first monolayer on the substrate. A second precursor gas different in composition from the first precursor gas is flowed to the first monolayer within the chamber under surface microwave plasma conditions within the chamber effective to react with the first monolayer and form a second monolayer on the substrate which is different in composition from the first monolayer. The second monolayer includes components of the first monolayer and the second precursor. In one implementation, the first and second precursor flowings are successively repeated effective to form a mass of material on the substrate of the second monolayer composition. Additional and other implementations are contemplated.

RELATED PATENT DATA

This patent resulted from a divisional application of U.S. patentapplication Ser. No. 10/293,072, filed on Nov. 12, 2002 now U.S. Pat.No. 7,022,605, entitled “Atomic Layer Deposition Methods”, and namingTrung Tri Doan, Guy T. Blalock and Gurtej S. Sandhu as inventors, thedisclosure of which is incorporated by reference.

TECHNICAL FIELD

This invention relates to atomic layer deposition methods.

BACKGROUND OF THE INVENTION

Semiconductor processing in the fabrication of integrated circuitrytypically includes the deposition of layers on semiconductor substrates.One such method is atomic layer deposition (ALD), which involves thedeposition of successive monolayers over a substrate within a depositionchamber typically maintained at subatmospheric pressure. With typicalALD, successive monoatomic layers are adsorbed to a substrate and/orreacted with the outer layer on the substrate, typically by thesuccessive feeding of different deposition precursors to the substratesurface.

An exemplary ALD method includes feeding a single vaporized precursor toa deposition chamber effective to form a first monolayer over asubstrate received therein. Thereafter, the flow of the first depositionprecursor is ceased and an inert purge gas is flowed through the chambereffective to remove any remaining first precursor which is not adheringto the substrate from the chamber. Subsequently, a second vapordeposition precursor, different from the first, is flowed to the chambereffective to form a second monolayer on/with the first monolayer. Thesecond monolayer might react with the first monolayer. Additionalprecursors can form successive monolayers, or the above process can berepeated until a desired thickness and composition layer has been formedover the substrate.

SUMMARY

The invention comprises atomic layer deposition methods. In oneimplementation, a semiconductor substrate is positioned within an atomiclayer deposition chamber. A first precursor gas is flowed to thesubstrate within the chamber effective to form a first monolayer on thesubstrate. A second precursor gas different in composition from thefirst precursor gas is flowed to the first monolayer within the chamberunder surface microwave plasma conditions within the chamber effectiveto react with the first monolayer and form a second monolayer on thesubstrate which is different in composition from the first monolayer.The second monolayer includes components of the first monolayer and thesecond precursor. In one implementation, the first and second precursorflowings are successively repeated effective to form a mass of materialon the substrate of the second monolayer composition. In oneimplementation, after the second precursor gas flowing, a thirdprecursor gas different in composition from the first and secondprecursor gases is flowed to the second monolayer within the chambereffective to react with the second monolayer and form a third monolayeron the substrate which is different in composition from the first andsecond monolayers. In one implementation, after the second precursor gasflowing, the first precursor gas is flowed to the substrate within thechamber effective to react with the second monolayer and both a) removea component of the second monolayer to form a third compositionmonolayer on the substrate which is different in composition from thefirst and second monolayers; and b) form a fourth monolayer of the firstmonolayer composition on the third composition monolayer.

Other aspects and implementations not necessarily generic to any of theabove are contemplated and disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described below withreference to the following accompanying drawings.

FIG. 1 is a diagrammatic sectional view of an exemplary atomic layerdeposition apparatus usable in accordance with an aspect of theinvention.

FIG. 2 is a series of diagrammatic molecular level views of an exemplarymethod in accordance with an aspect of the invention.

FIG. 3 is a series of diagrammatic molecular level views of an exemplarymethod in accordance with an aspect of the invention.

FIG. 4 is a series of diagrammatic molecular level views of an exemplarymethod in accordance with an aspect of the invention.

FIG. 5 is a series of common timelines showing exemplary gas flows andpower levels of processing in accordance with exemplary aspects of theinvention.

FIG. 6 is an alternate series of common timelines to that depicted byFIG. 5.

FIG. 7 is another alternate series of common timelines to that depictedby FIG. 5.

FIG. 8 is still another alternate series of common timelines to thatdepicted by FIG. 5.

FIG. 9 is yet another alternate series of common timelines to thatdepicted by FIG. 5.

FIG. 10 is another alternate series of common timelines to that depictedby FIG. 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

This disclosure of the invention is submitted in furtherance of theconstitutional purposes of the U.S. Patent Laws “to promote the progressof science and useful arts” (Article 1, Section 8).

FIG. 1 depicts an exemplary atomic layer deposition apparatus usable inaccordance with an aspect of the invention. Such an apparatus enablesthe generation of a surface microwave plasma within a chamber withinwhich atomic layer deposition is conducted relative to a semiconductorsubstrate. In the context of this document, “surface microwave plasma”is defined as a plasma generated in a gas against a substrate beingprocessed by transmitting microwave energy from a plurality of discrete,spaced microwave emitting sources, and whether conducted in existing oryet-to-be-developed manners. One existing manner of doing so is by useof an antenna, such as a surface plane antenna (SPA) or a radial lineslot antenna (RLSA). By way of example only, examples can be found inU.S. Pat. Nos. 6,399,520 and 6,343,565, which are hereby incorporated byreference herein.

Apparatus 10 is diagrammatically depicted as comprising a depositionchamber 12 having a semiconductor substrate 14 positioned therein. Inthe context of this document, the term “semiconductor substrate” or“semiconductive substrate” is defined to mean any constructioncomprising semiconductive material, including, but not limited to, bulksemiconductive materials such as a semiconductive wafer (either alone orin assemblies comprising other materials thereon), and semiconductivematerial layers (either alone or in assemblies comprising othermaterials). The term “substrate” refers to any supporting structure,including, but not limited to, the semiconductive substrates describedabove. A suitable support or mechanism (not shown) can be provided forsupporting substrate 14 therein, and which might be temperaturecontrolled, powered and/or otherwise configured for positioning asubstrate 14 within chamber 12 as desired.

A suitable microwave generator 16 is operatively connected with asurface plane antenna 18 received just above deposition chamber 12.Typically, surface plane antenna 18 is comprised of a metal materialhaving a plurality of microwave transmissive openings 20 formed thereinthrough which microwave energy generated by source 16 passes to withinchamber 12, and proximate the surface of substrate 14. The upper wall ofchamber 12 over which surface plane antenna 18 is received is also,therefore, provided to be microwave transmissive. Of course, some or allof surface plane antenna 18 could be provided within deposition chamber12. An exemplary preferred spacing from the upper surface of substrate14 to the lower surface of surface plane antenna 18 is 65 mm. Of course,greater or small spacings can be utilized. In certain situations,spacings considerably less than 65 mm might be utilized. Further, inaddition to microwave, energy generation is also contemplated incombination with microwave energy generation, and whether within orexternally of chamber 12.

Exemplary precursor and/or purge gas inlets 22 and 24 are showndiagrammatically for emitting precursor and/or purge gases to withinchamber 12 intermediate substrate 14 and surface plane antenna 18. Avacuum draw-down line 26 is diagrammatically shown for exhaustingmaterial from chamber 12. The FIG. 1 apparatus is diagrammatic andexemplary in construction only, with any other suitable apparatus beingusable in accordance with the methodical aspects of the invention. Forexample, any alternate configuration, such as showerheads, multipleports or other means, whether existing or yet-to-be developed, are alsoof course contemplated for getting gas to the chamber and exhaustingmaterial from the chamber.

A semiconductor substrate, such as substrate 14, is positioned within anatomic layer deposition chamber. A first precursor gas is flowed to thesubstrate within the chamber, for example through one or both of inlets22 and 24, effective to form a first monolayer on the substrate. By wayof example only, and with respect to forming an exemplary TiB₂ layer, anexemplary first precursor gas includes TiCl₄, and, for example, alone orin combination with inert or other gases. An exemplary first monolayerproduced from such TiCl₄ is TiCl_(x), for example as depicted relativeto FIG. 2. FIG. 2 illustrates exemplary sequential processing in anatomic layer deposition method utilizing TiCl₄. The far left illustratedportion of FIG. 2 depicts a suitable substrate surface 30 having a firstmonolayer 32 comprising TiCl_(x) adhered thereto. Such, by way ofexample only, is in the form of titanium adhering to substrate surface30 with chlorine atoms or molecules extending outwardly from thetitanium.

Typically, any remaining first precursor gas would then be purged fromthe chamber using an inert purge gas, or by some other method.Regardless, a second precursor gas, different in composition from thefirst precursor gas, is then flowed to the first monolayer within thechamber under surface microwave plasma conditions within the chambereffective to react with the first monolayer and form a second monolayeron the substrate which is different in composition from the firstmonolayer, with the second monolayer comprising components of the firstmonolayer and the second precursor. In the context of this document, agas being “different in composition” means some gas having an alternateand/or additional reactive component from the gas to which it is beingcompared.

The middle view in FIG. 2 depicts an exemplary preferred secondprecursor gas as comprising B₂H₆ and in an activated state under surfacemicrowave plasma conditions. As depicted in the far right view, such iseffective to react with first monolayer 32 to form a second monolayer 34which comprises TiB₂, with HCl as a by-product. Second monolayer 34comprises a component of the first monolayer (i.e., Ti) and a componentof the second precursor (i.e., B).

The above described first and second precursor flowings are successivelyrepeated effective to form a mass of material on the substrate of thesecond monolayer composition. The fabricated mass might comprise,consist essentially of, or consist of the second monolayer composition.For example, the invention contemplates the possibility of fabricatingthe mass to include materials other than solely the second monolayercomposition, for example by introducing alternate first and/or secondprecursor gases as compared to only using the above-described first andsecond precursor gases in forming the mass of material on the substrate.

The exemplary above-described process has the second monolayer componentfrom the first monolayer as being a metal in elemental form (i.e.,titanium), wherein the second monolayer comprises a conductive metalcompound. Further in one preferred embodiment, the mass of material isformed to be conductive. By way of example only, an alternate of suchprocessing would be to utilize a first precursor gas comprising TaCl₅ toform a first monolayer comprising TaCl_(x). In such instance, anexemplary second precursor gas comprises NH₃ to form a second monolayercomprising TaN. As with the first-described embodiment, inert gases,flow rates, power, temperature, pressure and any other operatingparameter can be selected and optimized by the artisan, with noparticular one or set of parameters being preferred in the context ofthe invention.

Alternately by way of example only, the second monolayer could be formedto comprise a dielectric material, and further by way of example only,the mass of material fabricated to be insulative. For example forforming an insulative mass comprising Al₂O₃, exemplary gases includetrimethylaluminum as a first precursor gas, and O₃ and/or H₂O as asecond precursor gas.

Also in any of the above-described and subsequent embodiments, the firstprecursor gas flowing can be with or without plasma within the chamber,for example with or without surface microwave plasma generation withinthe chamber with the first precursor gas flowing. Further, remote plasmageneration could also be utilized with the first precursor gas flowing,and also with the second precursor gas flowing in combination withsurface microwave plasma conditions within the chamber during the secondprecursor gas flowing.

In one implementation, an atomic layer deposition method includes theabove generically described first and second precursor gas flowings.After the second precursor gas flowing, a third precursor gas differentin composition from the first and second precursor gases is flowed tothe second monolayer within the chamber effective to react with thesecond monolayer and form a third monolayer on the substrate which isdifferent in composition from the first and second monolayer. The first,second and third precursor flowings can be successively repeatedeffective to form a mass of material on the substrate which comprises,consists essentially of or consists of the third monolayer composition.By way of example only in accordance with this implementation, exemplaryprocessing is further described with reference to FIG. 3 in theformation of a third monolayer comprising an aluminum oxide.

Specifically, the far left illustrated view of FIG. 3 depicts the resultof flowing a first precursor gas comprising trimethylaluminum to form afirst monolayer 40 comprising AlCH_(x) onto a substrate surface 30. Asecond precursor gas, for example H₂, is flowed to the first monolayerwithin the chamber under surface microwave plasma conditions within thechamber effective to react with first monolayer 40 and form a differentcomposition second monolayer 42 on the substrate. Illustrated secondmonolayer 42 comprises a component from first monolayer 40 (Al) and acomponent from the second precursor (H). A third precursor gas (i.e., O₃and/or H₂O) is flowed to second monolayer 42 within the chambereffective to react therewith and form a third monolayer 44 (i.e.,AlO_(x)) on substrate 30 which is different in composition from firstmonolayer 40 and second monolayer 42. Of course, such processing can berepeated to deposit a desired thickness aluminum oxide comprising layerby atomic layer deposition. Further of course, one, both or neither ofthe first and third precursor gas flowings could comprise remote and/orchamber generated plasma, and for example include surface microwaveplasma conditions.

By way of example only and where a desired finished product is TiN, anexemplary alternate first precursor gas is TiCl₄ to form a monolayercomprising TiCl_(x). An exemplary second precursor gas could stillcomprise H₂, with an exemplary third precursor gas comprising NH3.Further by way of example, another deposited material is TaN as thethird monolayer. An exemplary first precursor gas is TaCl₅ to form thefirst monolayer to comprise TaCl_(x). An exemplary second precursor gasis H₂ and an exemplary third precursor gas is NH₃.

In one implementation, processing occurs as described above genericallywith respect to the first and second precursor gas flowings. After thesecond precursor gas flowing, the first precursor gas is flowed to thesubstrate within the chamber effective to react with the secondmonolayer and both a) remove a component of the second monolayer to forma third composition monolayer on the substrate which is different incomposition from the first and second monolayers, and b) form a fourthmonolayer of the first monolayer composition on the third compositionmonolayer. By way of example only, exemplary processing is morespecifically described in FIG. 4 in connection with the fabrication ofan elemental tantalum layer.

The far left illustrated view of FIG. 4 depicts processing after flowinga first precursor gas comprising TaCl₅ to form a first monolayer 60comprising TaCl_(x) onto a substrate surface 30. This is followed byflowing a second precursor gas (i.e., H₂) which is different incomposition from the first precursor gas to the first monolayer withinthe chamber under surface microwave plasma conditions within the chambereffective to react with the first monolayer to form a second monolayer62 on the substrate which is different in composition from the firstmonolayer. Second monolayer 62 comprises a component of the firstmonolayer (i.e., Ta) and a component of the second precursor (i.e., H).Subsequently, the first precursor gas (i.e., TaCl₅) is flowed to thesubstrate within the chamber effective to react with second monolayer 62to both a) remove a component of the second monolayer (i.e., H) to forma third composition monolayer 64 (i.e., Ta), which is different incomposition from first monolayer 60 and second monolayer 62, and b) forma fourth monolayer 66 (i.e., TaCl_(x)) of the first monolayercomposition on third composition monolayer 64. Such can be successivelyrepeated to form a mass of material on the substrate comprising,consisting essentially of, or consisting of the third compositionmonolayer. Again, the first and third precursor flowings can be with orwithout plasma within the chamber, for example with or without surfacemicrowave plasma.

The depicted and preferred FIG. 4 processing forms the third compositionmonolayer to comprise a metal in elemental form. By way of example only,alternate exemplary processing for the fabrication of a titanium layermight utilize a first precursor gas comprising TiCl₄ to form the firstmonolayer to comprise TiCl_(x). In such instance, a preferred exemplarysecond precursor again comprises H₂.

The invention has particular advantageous utility where the firstmonolayer is of a composition which is substantially unreactive with thesecond precursor under otherwise identical processing conditions but forpresence of surface microwave plasma within the chamber. Firstmonolayers as described above with reference to FIGS. 2-4 can constitutesuch compositions.

At least with respect to a second precursor gas flowing which isdifferent from the first to form the first monolayer within the chamberunder surface microwave plasma conditions, the various above-describedprocessings can provide better uniformity and utilize lower ion energyin facilitating an atomic layer deposition which is plasma enhanced incomparison to higher ion energy plasmas which are not expected toprovide as desirable a uniformity.

The above-described processings can occur in any manner as literallystated, for example with or without intervening inert purge gas flowingsand under any existing or yet-to-be developed processing parameters.Further by way of example only, the openings within the antenna might bemade to be gas transmissive as well as microwave transmissive and theantenna provided with the chamber. In such instance, gas might be flowedthrough the plurality of openings while transmitting microwave energythrough the plurality of openings to the processing chamber effective toform a surface microwave plasma onto a substrate received within theprocessing chamber. Gas inlets could be configured to flow first to theantennas, and then into the chamber through the openings with themicrowave energy which is transmitted through the same openings, orthrough different openings. Such processing can be void of flowing anygas to the chamber during transmitting of the microwave energy otherthan through the plurality of openings, if desired.

Further by way of example only, exemplary preferred processing forcarrying out the above exemplary methods is described below inconjunction with TiCl₄ as a first precursor gas and H₂ as a secondprecursor gas, and utilizing an inert purge gas comprising helium. Thebelow-described preferred embodiments/best modes disclosure forpracticing exemplary methods as described above are also considered toconstitute independent inventions to those described above, and as aremore specifically and separately claimed.

Referring generally to FIGS. 5-9, such essentially depict a commonhorizontal timeline showing different respective gas pulses separatelybroken out in the form of a first precursor gas (i.e., TiCl₄), an inertpurge gas (i.e., He), and a second precursor gas (i.e., H₂). The H₂timeline also has associated therewith dashed lines intended to depictthe application of energy at least the elevated-most surfaces of whichare intended to depict a power level effective to form a plasma of theexemplary H₂ gas flowing within the chamber. Such might, and preferablydoes, constitute surface microwave plasma generation within a suitablechamber, for example as described above in connection with the firstabove embodiments, although is not so limited with respect to the FIGS.5-9 embodiments unless found literally in a claim under analysis.

Referring initially to FIG. 5, a semiconductor substrate would bepositioned within an atomic layer deposition chamber. A first precursorgas is flowed to the substrate within the chamber effective to form afirst monolayer on the substrate, for example as depicted by a TiCl₄ gaspulse P1. Plasma generation might or might not be utilized. Afterflowing the first monolayer, an inert purge gas is flowed to thechamber, for example as depicted by a helium gas pulse P2. After flowingthe inert purge gas, a second precursor gas is flowed to the substrateunder plasma conditions within the chamber effective to form a secondmonolayer on the substrate which is different in composition from thefirst monolayer, for example as depicted by an H₂ gas pulse P3. Thesecond precursor gas is different in composition from the firstprecursor gas.

The plasma conditions within the chamber comprise the application ofenergy to the chamber at some power level 40 capable of sustainingplasma conditions within the chamber with the second precursor gas P3.The application of such energy to the chamber commences along anincreasing power level 42 up to plasma capable power level 40 at a timepoint 44 prior to flowing the second precursor gas to the chamber, forexample as depicted at time point 45. In the exemplary depicted FIG. 5embodiment, the power level increasing along line 42 is continuous, andalso preferably at a substantially constant rate. The first monolayermight be formed in the presence or absence of plasma within the chamber.Further in one preferred embodiment in connection with FIGS. 5-9, andfor example as described in the initial embodiments, the secondmonolayer formed may result from a reaction with the first monolayer,with the second monolayer comprising components of the first monolayerand the second precursor. Further in the exemplary FIG. 5 depictedembodiment, inert purge gas flowing P2 and second precursor gas flowingP3 do not overlap. By way of example only, exemplary time periods forall pulses is one second. Although of course, greater, less and/orunequal times could be utilized.

After forming the second monolayer, another inert purge gas flowing P4(the same or different in composition in some way to that of the firstpurge gas) is begun prior to commencing a reducing of the plasma capablepower. For example, FIG. 5 depicts the P4 pulse commencing at a timepoint 46 which is before a time point 48 when a reducing from the plasmacapable power starts to occur.

In the depicted FIG. 5 embodiment, and by way of example only, secondprecursor pulse P3 and the other inert purge gas pulse P4 do notoverlap. Further, the second precursor gas flowing to the chamber isceased prior to commencing a reducing of the plasma capable power. Byway of example, such is depicted at a time point 50, where the secondprecursor gas flow is ceased, in comparison with later-in-time point 48where power begins to reduce from power level 40. The above exemplaryprocessing can be repeated, of course, for example as shown by gaspulses P5, P6 and P7.

Another exemplary embodiment is described with reference to FIG. 6. Aswith the FIG. 5 embodiment, a semiconductor substrate is positionedwithin an atomic layer deposition chamber and a first precursor gas isflowed to the substrate within the chamber effective to form a firstmonolayer on the substrate. Such is depicted by the exemplary P1 TiCl₄pulsing. After forming the first monolayer, a second precursor gas isflowed to the substrate under plasma conditions within the chambereffective to form a second monolayer on the substrate which is differentin composition from the first monolayer. The second precursor gas isdifferent in composition from the first precursor gas, and is depictedby P3 as an example only with respect to an exemplary H₂ secondprecursor gas flowing.

In FIG. 6, plasma generation of the second precursor gas within thechamber occurs from a second applied power level of energy 40 to thechamber which is capable of generating plasma within the chamber. Somesteady-state, first-applied power level of such energy is applied to thechamber at some point at least prior to applying the second-appliedpower level of such energy 40. An exemplary steady-state, first-appliedpower level 62 is depicted in FIG. 6 which is less than second-appliedpower level 40, with an increasing from first-applied power 62 tosecond-applied power level 40 occurring along a line 64.

In one preferred embodiment, steady-state first power 62 is insufficientto generate plasma from the flowing second precursor gas. In onepreferred embodiment, steady-state first power 62 is insufficient togenerate plasma from the flowing first precursor gas. In the depictedexemplary preferred FIG. 6 embodiment, steady-state first power 62 isapplied during first precursor flowing P1, and under conditionseffective to form a first monolayer on the substrate under non-plasmaconditions within the chamber. In one embodiment, first power level 62can be considered as a base power level of energy.

FIG. 6 also depicts a purge gas flowing P2 to the chamber intermediatefirst precursor gas flowing P1 and second precursor gas flowing P2, withsteady-state first power 62 being applied during purge gas flowing P2.Further, base power level 62 is raised to power level 40 during aportion of inert purge gas flowing P2.

In the preferred FIG. 6 embodiment, a purge gas flowing P4 occurs afterthe second precursor gas flowing P3, with a return to power level 62occurring during such purge gas flowing P4 and after a ceasing of flowof second precursor gas P3. The exemplary processing is depicted asbeing repeated in connection with gas pulses P5, P6 and P7, and providesbut one example of depositing one or more additional monolayers onto thesecond monolayer. FIG. 6 depicts commencing the raising or increasing ofthe power level at a point in time 66 which is prior to a point in time68 when second precursor gas flowing P3 begins. Further in the preferredFIG. 6 embodiment, reducing from power level 40 is commenced at a timepoint 70 which occurs after a time point 72 where second precursor gaspulse P3 flow is ceased.

By way of example only, FIGS. 5 and 6 illustrate exemplary preferredembodiments wherein the respective gas pulses in no way overlap. Theinvention also contemplates at least some overlapping of the gas pulses,of course. By way of example only, and particularly with reference tothe second precursor gas pulsing, exemplary overlappings are describedwith reference to FIGS. 7-10.

Referring initially to FIG. 7, such is the same as FIG. 6 except theinert P2 pulse is extended to continue over the P3 pulse, with the inertP2 pulse flowing ceasing after a ceasing of second precursor gas flowingP3.

Referring to FIG. 8, a first precursor gas is flowed to the substratewithin an atomic layer deposition chamber effective to form a firstmonolayer on the substrate, for example as depicted with respect toTiCl₄ with a gas pulse P1. After forming the first monolayer, an inertpurge gas is flowed to the chamber, for example as designated by heliumgas pulse P2. After flowing the inert purge gas, a second precursor gasis flowed to the substrate under plasma conditions within the chambereffective to form a second monolayer on the substrate which is differentin composition from the first monolayer. In some manner, the secondprecursor gas is different in composition from the first precursor gas,for example as depicted in FIG. 8 by H₂ pulse P3.

As also depicted in FIG. 8, the second precursor gas flowing underplasma conditions within the chamber commences at an exemplary timepoint 76 before a time point 77 when inert purge gas flow P2 is ceased.Further, inert purge gas flow P2 ceases at the exemplary time point 77after the commencing and while the second precursor gas flowing underplasma conditions within the chamber is occurring. Further, FIG. 8depicts that the plasma conditions within the chamber comprise theapplication of energy to the chamber at a power level 40 which iscapable of sustaining plasma conditions within the chamber with thesecond precursor gas. FIG. 8 also depicts a minimum application of abase power level 62, and a raising therefrom to power level 40 along asegment 78. However also with respect to the FIG. 8 exemplaryembodiment, an aspect of the invention contemplates zero power beingapplied as opposed to some base level 62. Regardless and in anon-limiting fashion, FIG. 8 also depicts second precursor gas pulse P3commencing at a time point 80 and the power level increasing along line78 commencing at a time point 82 which is after time point 80.

After forming the second monolayer, another inert purge gas flow P4 isdepicted as commencing at a point in time 84 which is prior to a pointin time 86 when the second precursor gas flow is ceased. Of course, suchprocessing can be repeated for example as depicted by gas pulses P5, P6and P7.

By way of example only, FIG. 9 depicts an alternate embodiment wherebythe commencing of an application of energy to the chamber at theincreasing power level up to a plasma capable power level 40 occurscommensurate with point in time 80 constituting the beginning of theflow of the second precursor gas to the chamber. Also by way of exampleonly, FIG. 8 depicts power levels starting from and returning to zero,with the arrival at zero power also occurring at time point 86 when theflow of the second precursor is ceased.

Further by way of example only, FIG. 10 depicts a process whereby theapplication of energy to the chamber at the increasing power level up topower level 40 commences at a time point 90 which is prior to time point80 when the flow of the second precursor gas to the chamber commences.

By way of example only, plasmas generated from microwaves are typicallycharacterized by a very shallow skin depth, with the power being veryeffectively consumed in a very small volume. Surface microwave plasmatypically results from generation of uniform plasma from microwave bymeans of distributing or spreading out the microwave energy prior toentry into the reaction chamber. The microwave power is typicallyconverted from a waveguide transmission mode into waves that runparallel to an upper reactor plane antenna/window. This conversion tosurface wave is produced by a diverting antenna that acts to reflect themicrowaves. Once the microwaves are running parallel to the upper planeantenna, small openings in the plane antenna allow portions of themicrowave to be released to the reaction chamber thus spreading thepower over the desired area. The periodicity of the openings in theplane antenna determine the locality and uniformity of the power spread.

In compliance with the statute, the invention has been described inlanguage more or less specific as to structural and methodical features.It is to be understood, however, that the invention is not limited tothe specific features shown and described, since the means hereindisclosed comprise preferred forms of putting the invention into effect.The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

1. An atomic layer deposition method comprising: positioning asemiconductor substrate within an atomic layer deposition chamber;flowing a first precursor gas to the substrate within the chambereffective to form a first monolayer on the substrate, the flowing thefirst precursor gas being conducted under a condition of surfacemicrowave plasma within the chamber; flowing a second precursor gasdifferent in composition from the first precursor gas to the firstmonolayer within the chamber under surface microwave plasma conditionswithin the chamber effective to react with the first monolayer and forma second monolayer on the substrate which is different in compositionfrom the first monolayer, the second monolayer comprising components ofthe first monolayer and the second precursor; and successively repeatingsaid first and second precursor flowings effective to form a mass ofmaterial on the substrate of the second monolayer composition.
 2. Themethod of claim 1 wherein the first precursor gas comprises TiCl₄ andthe first monolayer comprises TiCl_(x).
 3. The method of claim 1 whereinthe first monolayer is of a composition which is substantiallyunreactive with the second precursor under otherwise identicalprocessing conditions but for presence of surface microwave plasmawithin the chamber.
 4. The method of claim 1 wherein the first precursorgas comprises TaCl₅ and the first monolayer comprises TaCl_(x).
 5. Themethod of claim 1 wherein the component of the first monolayer comprisesa metal in elemental form.
 6. The method of claim 1 wherein the secondmonolayer comprises a conductive metal compound, and the mass ofmaterial is conductive.
 7. The method of claim 1 wherein the secondmonolayer comprises a dielectric, and the mass of material isinsulative.
 8. An atomic layer deposition method comprising: positioninga semiconductor substrate within a deposition chamber; flowing a firstprecursor gas to the substrate within the chamber effective to form afirst monolayer on the substrate; providing sufficient power to producesurface microwave plasma generating conditions within the chamber andsubsequently flowing a second precursor gas different in compositionfrom the first precursor gas to the first monolayer within the chamberunder the surface microwave plasma conditions, the surface microwaveplasma conditions being produced within the chamber by transmittingmicrowave energy from a plurality of discrete, spaced microwave sourceswhile the second precursor gas is against the substrate, the surfacemicrowave plasma conditions being effective to react with the firstmonolayer and form a second monolayer on the substrate which isdifferent in composition from the first monolayer, the second monolayercomprising components of the first monolayer and the second precursor;and after the second precursor gas flowing, flowing the first precursorgas to the substrate within the chamber effective to react with thesecond monolayer and both a) remove a component of the second monolayerto form a third composition monolayer on the substrate which isdifferent in composition from the first and second monolayers, the thirdcomposition monolayer comprising a metal in elemental form; and b) forma fourth monolayer of the first monolayer composition on the thirdcomposition monolayer.
 9. The method of claim 8 wherein the removedcomponent comprises hydrogen.
 10. The method of claim 8 wherein thefirst precursor gas flowing is void of plasma within the chamber. 11.The method of claim 8 wherein the first precursor gas flowing comprisessurface microwave plasma within the chamber.
 12. The method of claim 8wherein the first precursor gas comprises TiCl₄, the first monolayercomprises TiCl_(x), the second precursor comprises H₂, and the thirdcomposition monolayer comprises elemental titanium.
 13. The method ofclaim 8 wherein the first precursor gas comprises TaCl₅, the firstmonolayer comprises TaCl_(x), the second precursor comprises H₂, and thethird composition monolayer comprises elemental tantalum.
 14. An atomiclayer deposition method, comprising; positioning a semiconductorsubstrate within a deposition chamber; flowing a first precursor gas tothe substrate within the chamber effective to form a first monolayer onthe substrate; after forming the first monolayer, flowing an inert purgegas to the chamber; after flowing the inert purge gas, flowing a secondprecursor gas to the substrate under plasma conditions within thechamber, the inert purge gas flowing overlapping the second precursorgas flowing, the plasma conditions generating a plasma from the secondprecursor gas within the chamber utilizing a plurality of discrete,spaced energy sources, the plasma conditions being effective to form asecond monolayer on the substrate which is different in composition fromthe first monolayer, the second precursor gas being different incomposition from the first precursor gas, said plasma conditionscomprising application of energy to the chamber at a power level capableof sustaining plasma conditions within the chamber with the secondprecursor gas; and providing power during the deposition method, theproviding power comprising: commencing application of said energy to thechamber prior to flowing the first precursor; providing power at acontinuous first level during the flowing the first precursor, andincreasing the power level up to said plasma capable power level priorto flowing the second precursor gas to the chamber.
 15. The method ofclaim 14 further comprising ceasing the inert purge gas flowing after aceasing of the second precursor gas flowing.
 16. The method of claim 14comprising after forming the second monolayer, commencing another inertpurge gas flowing prior to commencing a reducing of the plasma capablepower.
 17. The method of claim 16 wherein the second precursor andanother inert purge gas flowings do not overlap.
 18. The method of claim14 comprising ceasing flow of the second precursor gas to the chamberprior to commencing a reducing of the plasma capable power.
 19. Themethod of claim 14 comprising: after forming the second monolayer,commencing another inert purge gas flowing prior to commencing areducing of the plasma capable power; and ceasing flow of the secondprecursor gas to the chamber prior to commencing said reducing of theplasma capable power.
 20. The method of claim 14 wherein the plasmaconditions comprise surface microwave plasma.
 21. The method of claim 14wherein said increasing is continuous.